Ministry investigates dead fish at Walvis
ELLANIE SMIT
WINDHOEK
The fisheries ministry is conducting a water analysis to identify the phytoplankton species present in the Walvis Bay lagoon and harbour areas to determine whether they are toxic or not.
This after many dead or dying mullet fish were observed in the Walvis Bay lagoon area on Sunday, while a high number of jellyfish have also washed up at the Swakopmund Mole and Walvis Bay beaches recently.
The ministry cautioned the public against consuming the washed-up fish until the cause of death has been established.
According to fisheries ministry executive director Annely Haiphene, satellite images show algal blooms along the central Namibian coast and water temperatures around 25 degree Celsius.
This, she said, is usual for this time of the year, because of weakened south-westerly winds and consequently no active upwelling taking place, leading to local warming of the water as well as the intrusion of warmer oceanic water into the coastal areas, which are favourable for algal blooms.
According to her, algal blooms can be toxic, but even non-toxic species strip the water column of oxygen when decaying and can lead to low oxygen events that are sometimes exacerbated by sulphur eruptions.
Jellyfish stings
“Low oxygen conditions are presumed to have trapped the fish in the lagoon and along the coast, causing them to die and wash out when the water level drops during low tide.”
With regards to the jellyfish, she said the warm oceanic water presently along the central coast transports many jellyfish which are then trapped in bays or wash up on beaches.
“When humans get in touch with the tentacles of these live jellyfish while swimming, the jelly inflicts a painful sting on the skin which can be sore, but it is not harmful.”
Rubbing the area will increase and prolong the burning and should be avoided, Haiphene said.
[email protected]
WINDHOEK
The fisheries ministry is conducting a water analysis to identify the phytoplankton species present in the Walvis Bay lagoon and harbour areas to determine whether they are toxic or not.
This after many dead or dying mullet fish were observed in the Walvis Bay lagoon area on Sunday, while a high number of jellyfish have also washed up at the Swakopmund Mole and Walvis Bay beaches recently.
The ministry cautioned the public against consuming the washed-up fish until the cause of death has been established.
According to fisheries ministry executive director Annely Haiphene, satellite images show algal blooms along the central Namibian coast and water temperatures around 25 degree Celsius.
This, she said, is usual for this time of the year, because of weakened south-westerly winds and consequently no active upwelling taking place, leading to local warming of the water as well as the intrusion of warmer oceanic water into the coastal areas, which are favourable for algal blooms.
According to her, algal blooms can be toxic, but even non-toxic species strip the water column of oxygen when decaying and can lead to low oxygen events that are sometimes exacerbated by sulphur eruptions.
Jellyfish stings
“Low oxygen conditions are presumed to have trapped the fish in the lagoon and along the coast, causing them to die and wash out when the water level drops during low tide.”
With regards to the jellyfish, she said the warm oceanic water presently along the central coast transports many jellyfish which are then trapped in bays or wash up on beaches.
“When humans get in touch with the tentacles of these live jellyfish while swimming, the jelly inflicts a painful sting on the skin which can be sore, but it is not harmful.”
Rubbing the area will increase and prolong the burning and should be avoided, Haiphene said.
[email protected]
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